This invention relates to an apparatus for flame spraying, in particular of powder materials by means of an autogenous flame, comprising a nozzle carrier which has a burner nozzle and which can be connected to a preferably tubular accelerating accessory device which is provided with coolant guide means surrounding the burner nozzle.
Flame spraying apparatuses with accessory devices for post-acceleration of the flame are known. A problem which consistently occurs in relation to such flame spraying apparatuses is reliable ignition and adjustment of the flame. Various procedures have been developed for that purpose, for example igniting the flame by means of a sparking plug or an igniter device; that kind of construction suffers from the risk of explosion as the volume of gas in the accelerating tube is relatively great. Another design configuration involves pivoting the accelerating tube away, with the flame being ignited with the tube in the pivoted-away condition. A problem with that arrangement is that, when the accelerating tube is pivoted back into position over the flame, disturbances can occur in the flame, resulting in irregularity of the flame.
The above-described measures did not provide the improvement which had been hope for, in regard to reliability and safety of flame spraying appartuses. Furthermore, adjustment of the flame to provide a normal, an oxidising or a reducing flame, is only limitedly possible.
A further problem with the known accelerating accessory devices is the fact that they cannot be adequately tuned or matched to the powder spray material to be used.
In view of those considerations, the inventor set himself the aim of eliminating the above-indicated deficiencies on an improved apparatus of the kind set forth hereinabove.